The 41-year-old Brooklynite (pictured) plucks thrown-away MetroCards from platforms and garbage cans and claims he’s earned $20,000 reselling them over the past few years. Now he’s fighting the MTA for his right to do so.

“I’m surprised that people just toss money away,” Jones said.

Once a week, Jones combs the city’s busiest transit hubs for cards with leftover funds — part of $52 million in annual unused MetroCards.

“We’re not just walking on millions; we’re throwing it in the trash, too,” said Jones, a volunteer for the homeless.

During the holiday season he pocketed $1,500 worth of MetroCards in Times Square, Penn Station, Grand Central and Rockefeller Center.

“I managed to sell about half of that,” he said, pulling out a thick wad of remaining cards worth $700, which he plans to sell in the coming weeks.

The average value left on a card that Jones finds is $1.70. He combines multiple cards into one $5 card, then sells it to a straphanger for $4.

The subterranean entrepreneur began his MetroCard moonlighting 10 years ago, he said, after roaming around Grand Central Station and finding a MetroCard on the ground. “It had $33 on it,” he recalled. “That was when the fare was $1.50. From that day on, I’ve been doing it.”

He said he hasn’t paid for a subway ride since then.

But the MTA doesn’t like Jones’ enterprise.

Cops arrested him on Nov. 30 and again on Dec. 2, charging him with unlawful solicitation and illegal access to transit services. He plans to fight all the charges when he’s in court on Jan. 25.